I bought 2 games for a relative low price on Ebay. 8.75€ each with an extra 5.60€ for shipping (paid once). Unfortunately those games was counteract. It is not a big deal for the price but I think I preferred to know it before. This is screen capture of the item on ebay

English translation :

The Legend of Zelda Oracle of Ages Game. Works on any American, Japanese or European Nintendo Game Boy.
It works and saves the game perfectly. All our games have been tested in order to check their correct operation before being sold.
Magnificent game of the Zelda saga. Personally our favorite saga of this generation of consoles.
A must within the retro games.

Here are picture of the cartridge :

Plastic are cheap, soft and not to the right color. Screw are not the same as original game. I see that the plastic is not flat, but bended by something inside.

Inside the cartridge :

Very small PCB are inside and I understand what is bumping the plastic. Battery is a bit too high.
Pcb are relative good produced and contact are gold plated.

One cartridge containing :

• Mitsubitch M5M5256 – 256K of SRAM
• One ST M29W640D – FLASH NOR 64 MB in TFBGA48
• One small unknown chip

It is strange but the other is a bit different with :

• Cypress 256K (32K x 8) Static RAM
• One ST M29W640D – FLASH NOR 64 MB in TFBGA48
• One small unknown chip

Testing :

All seems to work great, gaming boot and are saving good. Good surprise game are in multiples language and not just US version (as the sticker say)